Tow system for water sking and the like



April 9, 1968 J. T. HANCOCK TOW SYSTEM FOR WATER SKIING AND THE LIKE Filed Aug. 15, 1 966 2 Sheets-Sheet l INVENTOR. JOH N T. HANCOCK ATTORNEYS April 9, 1968 J. T. HANCOCK TOW SYSTEM FOR WATER SKIING AND THE LIKE 2 Sheets-Sheet 2 Filed Aug. 15, 1966 FIG. 5

FIG. 4

INVENTOR. JOHN T. HANCOCK ATTORNEYS United States Patent T 3,376,829 TOW SYSTEM FOR WATER SKIING AND THE LIKE John T. Hancock, Jefierson County, Colo. (8750 W. Dakota Ave., Denver, Colo. 80226) Filed Aug. 15, 1966, Ser. No. 572,566 8 Claims. (Cl. 104-473) This invention relates to towing equipment suitable for water skiing and the like and particularly to such towing system including an improved arrangement for accelerating a skier to bring his speed up to the towing speed of the system.

Several types of fixed course towing systems have been provided heretofore which make it possible to practice water skiing and the like without employing a boat to tow the skier. These systems include both endless cable drives and individual motor drives. The speeds required for water skiing are substantially greater than those required for the ski lifts employed to take skiers uphill for downhill snow skiing. The greater speeds required for water skiing tows introduce problems incident to bringing the skiers up to the required speed with safety and minimum discomfort. Some of the systems are quite complicated and others have not proved entirely satisfactory for all applications. Accordingly, it is an object of this invention to provide an improved towing system for water skiing and the like which is of simple and rugged construction and is easy to maintain in operation.

It is another object of this invention to provide a towing system for water skiing and the like including an improved arrangement for accelerating the user to the full speed of the system without reducing the speed of the main system drive.

It is another object of this invention to provide a water ski towing system or the like including a main cable driven at substantially constant speed and an improved arrangement for bringing a person using the system up to the speed of the system.

It is a further object of this invention to provide an improved towing system for water skiing which is easy and safe to use.

Briefly, in carrying out the objects of this invention in one embodiment thereof, a continuous cable is mounted in position to extend along the course over which water skiers are to be towed. The cable is carried by large diameter sheaves mounted on towers rigidly secured in positions at the corners or turns of the course. The system is built to include a straight run portion extending directly away from the shore or starting point for the skiers and an acceleration system comprising a second cable mounted adjacent the straight portion of the first cable and parallel with and close to the main cable. The cables are driven in a direction such that the straight portions move away from the shore or starting position.

A hook is provided on the acceleration cable and a plurality of cone-shaped stops are securely attached to the main cable at desired intervals. The towline for the skier is provided with a handle at one end and with a cable attaching device at the other end which includes a hook for looping over the main cable which has an internal diameter less than the maximum diameter of the cone-shaped stop and with a hook portion for engagement with a hook on the acceleration cable.

When the system is in use the main cable is driven at the predetermined desired speed for the skier and the acceleration system is operated whenever a new skier is to be connected to the main cable. The skier grips the handle ofa towline and the rope is placed in the hook on the stationary acceleration cable while the hook on the device is placed in position over the moving main cable so that it will be picked up by the faster forward 3,376,829 Patented Apr. 9, 1968 movement of the stop on the main cable. The acceleration cable is started when a stop on the main cable is about to come into position along the straight starting section, and the skier is accelerated to a speed somewhat less than the speed of the main cable. When the main cable at this greater speed passes the device it picks up the device and carries it forward moving the skier away from the starting zone at the full speed of the main cable While at the same time releasing the device from the hook on the acceleration cable. Safety controls are provided in order to prevent actuation of the acceleration cable in the event that a towline has not been released from the stop on the main tow which is moving into position to pick up a skier.

The features of novelty which characterize this invention are pointed out with particularity in the claims annexed to and forming a part of this specification. The invention itself, however, both as to its organization and manner of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which:

FIG. 1 is an overall perspective view of a water ski tow system embodying the invention;

FIG. 2 is an enlarged perspective view of a portion of the system shown in FIG. l'showing a skier about to be picked up by the main tow;

FIG. 3 is an enlarged view of the attaching hook portion of the auxiliary tow on the system of FIG. 1;

FIG. 4 is an enlarged elevation view of the attaching device for the towline of the system of FIG. 1 illustrating a sequential position in dotted lines;

FIG. 5 is an enlarged perspective view of a portion of the cable showing the towline attaching device approaching the end of the course;

FIG. 6 is an enlarged perspective view showing the signal actuator for initiating or readying the starting operation of the accelerator system; and

FIG. 7 is a schematic diagram of the electrical connections of the control for the tow system.

Referring now to the drawings, FIG. 1 illustrates a tow system 10 comprising a main cable 11 mounted on a plurality of large diameter sheaves 12 each of which is rigidly secured for rotation on a tower or pylon 13 which is offset sufficiently that the vertical leg thereof is not in the path of the skiers. The system includes a starting platform or ramp 14 arranged near the shore in line with a straight portion 15 of the main cable 11 and adjacent a smaller endless cable 16 which is mounted on two sheaves 17 similar to the sheaves 12 and which in turn are mounted on towers or pylons 18. The cable 16 is arranged with one portion closely adjacent the straight portion 15 of the main cable and the two cables are driven in a manner to be described below so that the adjacent portions move outwardly from the starting point 14. In order to maintain adequate tension on the mainv cable 11 a counterweight 20 is mounted on a pulley 21 secured to a tower 22 and arranged to draw a sheave 23 taut against a loop in the cable between two of the sheaves 12.

The cable 16 and its mountings comprise the skier acceleration system for the main system 10, and an arrangement is provided whereby the skier is accelerated by driving the cable 16 in synchronism with the positioning of a pickup member on the cable 15 so that the skier is brought from the starting point 14 forward along the straight portion 15 of the main cable at a rate suflicient to be picked up easily and gently by the main cable which is driven at a greater speed than the cable 16.

As shown in FIG. 2, the cables are driven by a motor 25 mounted on a stationary platform 26 carried by the pylons 13 and 18 adjacent the acceleration system. The motor 25 drives the main cable through V-belts 27 and a worm drive 28 which drives the portion toward the right as viewed in FIG. 2. The motor also drives a clutch mechanism through V-belts 31 and when the clutch mechanism is operated it connects a worm drive 32 to drive the sheave 17 mounted on the platform 26; this drive moves the side of the cable 16 adjacent the straight portion 15 in the same direction as the portion 15. The clutch 30 may be of any suitable type such as a fluid clutch which will pick up gradually and smoothly and accelerate the cable 16 at the desired rate to bring it up to a desired speed approaching that of the cable portion 15.

In order to pick up a skier and transfer him to the main cable, a device 33 is provided at one end of a towline 34 the other end of which has a handle 35 to be gripped by the skier. The device 33 is placed in engagement with a forwardly facing hook 37 rigidly secured to the cable 16, as indicated in FIG. 3, and an open hook 38 at the top of the device 33 is hooked over the straight portion 15 of the main cable. The device 33 also includes a float or buoyancy member 40 which keeps the towline and assembly floating when it falls in the water. The hook 38 is rigidly attached by a bar passing through the float member 40 and terminating in an inclined portion 41 at the bottom, the towline 34 being attached by a suitable loop 42 to the portion 41. Because the portion 41 is connected to the towline, the tension on the line as the skier is moved holds the device 33 in position with the portion 41 extending toward the rear and in this position the hook 38 extends with its plane transverse to the cable 15 and in a position to be picked up by one of a plurality of cone-shaped stops 43. These stops are rigidly attached to the main cable at intervals sufficient to carry skiers at safe distances from one another.

As the skier is drawn forward and the device 33 is I accelerated, it reaches a speed approaching that of the cable 15 at the time the device 43 catches up with the device 33 and engages the hook 38. The greater speed of the cable 15 is then imparted to the skier through the towline and the device 33 is drawn away out of engagement with the hook 37 which opens forward in the direction of travel of the cables.

As shown more clearly in FIGS. 4, 5 and 6, the pickup device or conical stop member 43 is provided with an annular groove 44 toward the larger end of the conical portion and the stop terminates in a cylindrical portion 45. The annular groove 44 is dimensioned to receive the hook 38 and to hold the hook upright as it moves with the cable. Thus the position of the inclined portion 41 remains substantially the same throughout the period of towing the skier from the starting point around to the finish line or dropping point which is located on the straight portion of the line indicated at 46 in FIG. 1.

FIG. 4 illustrates in full lines the position of the stop member 43 as it approaches a towing device 33 carried by the hook 37 on the acceleration cable 16. When the stop 43 moves forward into the hook the hook is dropped into the annular groove 44 as indicated in the dotted line portion of the figure and the device 33 moves away from the hook 37 as indicated. The towline is then securely attached to the main cable 11 and the skier is drawn along the course determined by the main cable and may zigzag back and forth within the limits set by the length of the towline.

As the skier approaches the end of the course he rounds the last corner following the straight portion of the main cable shown on the opposite side from the portion 15 in FIG. 1, and as he proceeds between the two sheaves 12 at the left-hand end of this figure, the device 33 strikes a lifting cam 47 which engages the device 33 below the float member 40 and lifts the float member thereby lifting the hook 38 from the annular groove 44 on the stop member 33. The cam 47 is arranged to move the device 33 outwardly of the main loop 10 together with its upward movement and this moves the hook 38 completely out of engagement with the stop 43 thereby releasing the towline and leaving the skier to coast to shore. In most cases the skier will drop the towline and start his coast to the shore before the device 33 reaches the lifting cam 47.

In the event that the towline is not released by the ramp or cam 47, the device 33 strikes a wand 50 connected to a control 51 which actuates the control of the system to prevent operation of the accelerating system to start another skier. If the device 33 has been released from the line, however, it continues until it strikes a roller 52 mounted on an arm 53 pivoted on a shaft 54 as indicated in FIG. 6, this shaft being suitably mounted an an arm or platform secured to the adjacent one of the pylons 13 by supporting brackets not ilustrated in the drawings. The stop 43 on striking the roller 52 moves the arm 53 laterally and actuates a control for affording operation of the clutch 30 whereby the next skier may be started on his trip around the course by operation of the acceleration cable 16. In the event that the operation of the acceleration system is stopped because of the striking of the wand 50 by the tow device, the system must be restored by removing the obstacle, whether the device 33 or some other obstacle, before it can be started again to enable the operator to control the acceleration system.

An electrical control circuit suitable for use in connection with the system as described above is illustrated by way of example in FIG. 7. This system is provided with power from a stepdown transformer 56 the secondary of which is connected across lines 57 and 58 to sup ply control voltage, a fuse 59 being provided to open the circuit in the event of overload.

In operation the acceleration system is controlled by the clutch 30 which is actuated by a solenoid 61 arranged to be connected across the lines 57 and 58 by a relay control switch 62. The switch 62 is actuated by energization of a relay coil 63 which can be energized when a manual control switch '64 is closed. This manual control switch together with the relays and other components of the switching circuit shown in FIG. 7 may be arranged in a console indicated at 65 in FIG. 2 and which is positioned where the operator can observe the entire system and particularly the loading area for the acceleration system.

The wand 50 and control 51 are arranged so that when the wand is depressed it closes a switch 66 and energizes a relay coil 57 of the control 51 by connecting it between the lines 57 and 58 through the upper blade of the switch 64. Energization of the coil 67 actuates the control 51 opening a switch 68 and closing a switch 69 which provides a holding circuit for the coil 67. Actuation of the control in this manner by opening the switch 68 prevents energization of the clutch operating relay coil 63 so that the clutch cannot be operated when an obstacle has engaged the wand 50. In the event the wand 50 is not engaged, the normally closed switch 68 remains closed 'and the cone or stop 43 engages the roller 52 and closes a switch blade 71 actuated by the roller. The closin g of this switch energizes the winding 63 by connecting it between the lines 57 and 58, the lower blade of the switch 64 and the normally closed blade of the switch 68 being closed. 'Energization of the coil 63 closes switches 72 and 73, the switch 72 providing a holding circuit for the coil 63 'a nd the switch 73 energizing the relay 61 to actuate the clutch 30 and start the acceleration system in operation.

If the operator for any reason desires to prevent operation of the acceleration system, he need only operate the switch 64 to prevent energizing of the clutch coil 61 so that the acceleration system cannot be operated. Whenever the switch 64 is opened the coil 63 is de-energized and the clutch actuating switch 73 drops out thereby preventing energization of the clutch operating coil 61. After stopping the system in this manner it is necessary that the operator again close the switch 70 normally actuated by the roller 52 upon movement of a cone 43 into position or to wait until the next stop 43 engages the roller. During the normal operation of the system in the event of such stopping, the skier about to leave the ramp must wait for the next cone stop 43 to come into position and again engage the roller 52 to close the switch 70 and thereby energize the coils 63 and 61 in order and operate the acceleration system.

From the foregoing it will be apparent that this invention has provided a water ski towing system which may be operated effectively to maintain the main towing cable in operation at full speed While allowing skiers to be connected to the cable by means of the acceleration system and further that the control of the system automatically prevents operation of the acceleration system to admit a skier to the system when any obstruction or failure of a preceding skier to leave the system may cause interference.

While the invention has been illustrated and described in connection with a specific arrangement of a ski tow system, various other modifications and applications will occur to those skilled in the art. Therefore, it is not desired that the invention be limited to the specific details illustrated and described and it is intended by the appended claims to cover all modifications which fall Within the spirit and scope of the invention.

I claim:

1. A system for towing water skiers and the like over the surface of a body of water comprising:

a main cable extending around the course to be followed by a water skier,

a starting zone for the skier,

an acceleration cable adjacent said starting zone,

said main and acceleration cables having straight parallel closely spaced portions extending away from said starting zone in the direction of movement of the cables,

means for driving said main cable at a predetermined speed,

means for driving said acceleration cable to move said straight portion thereof in the same direction as the main cable and with acceleration up to a speed approaching said predetermined speed,

a towline for a skier having a grip at one end and an attaching device at its other end,

stop means on said acceleration cable for attaching said device thereto for towing a skier,

stop means on said main cable for engaging said device upon overtaking it when it is attached to said acceleration cable and for detaching said device from said acceleration cable and securing it to said main cable, whereby a skier gripping said towline and moving with said acceleration cable on said straight portion thereof is picked up and transferred to said main cable upon engagement of said device by said means on said main cable.

2. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 1 wherein said stop means on said acceleration cable comprises a forwardly facing hook for engaging a part of said attaching device, and wherein said stop means on said main cable comprises a cone-shaped stop having its axis concentric with that of said cable and having its smaller end forwardly in the direction of movement of said cable, said device including a hook for encircling said main cable and having an opening sufiicient to provide release therefrom.

3. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 2 whereinsaid cone-shaped stop has an annular recess thereon spaced from the forward end thereof for receiving and retaining said hook on said device.

4. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 3 including lifting means positioned adjacent said main cable near the end of said course for removing said hook from said annular recess on said main cable stop.

5. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 1 including means for connecting said acceleration cable to be driven by the said driving means of said main cable and clutch means for controlling the speed of said acceleration cable and the pickup of the skier.

6. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 1 wherein said main cable is supported above the Water and wherein the straight portion of said acceleration cable lies below the parallel straight portion of said main cable and including means for releasing said hook from said main cable near the end of said course for dropping the towline from said main cable.

7. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 1 including means for preventing operation of said acceleration cable prior to the release of the towline from said main cable at the end of said course.

8. A system for towing water skiers and the like over the surface of a body of water as set forth in claim 1 including means for preventing operation of said acceleration cable until a stop on the main cable reaches a predetermined point on said course.

References Cited UNITED STATES PATENTS 9/1962 Pomagalski 104-173 6/1965 Forsman 104-173 

1. A SYSTEM FOR TOWING WATER SKIERS AND THE LIKE OVER THE SURFACE OF A BODY OF WATER COMPRISING: A MAIN CABLE EXTENDING AROUND THE COURSE TO BE FOLLOWED BY A WATER SKIER, A STARTING ZONE FOR THE SKIER, AN ACCELERATION CABLE ADJACENT SAID STARTING ZONE, SAID MAIN AND ACCELERATION CABLES HAVING STRAIGHT PARALLEL CLOSELY SPACED PORTIONS EXTENDING AWAY FROM SAID STARTING ZONE IN THE DIRECTION OF MOVEMENT OF THE CABLES, MEANS FOR DRIVING SAID MAIN CABLE AT A PREDETERMINED SPEED, MEANS FOR DRIVING SAID ACCELERATION CABLE TO MOVE SAID STRAIGHT PORTION THEREOF IN THE SAME DIRECTION AS THE MAIN CABLE AND WITH ACCELERATION UP TO A SPEED APPROACHING SAID PREDETERMINED SPEED, A TOWLINE FOR A SKIER HAVING A GRIP AT ONE END AND AN ATTACHING DEVICE AT ITS OTHER END, STOP MEANS ON SAID ACCELERATION CABLE FOR ATTACHING SAID DEVICE THERETO FOR TOWING A SKIER, STOP MEANS ON SAID MAIN CABLE FOR ENGAGING SAID DEVICE UPON OVERTAKING IT WHEN IT IS ATTACHED TO SAID ACCELERATION CABLE AND FOR DETACHING SAID DEVICE FROM SAID ACCELERATION CABLE AND SECURING IT TO SAID MAIN CABLE, WHEREBY A SKIER GRIPPING SAID TOWLINE AND MOVING WITH SAID ACCELERATION CABLE ON SAID STRAIGHT PORTION THEREOF IS PICKED UP AND TRANSFERRED TO SAID MAIN CABLE UPON ENGAGEMENT OF SAID DEVICE BY SAID MEANS ON SAID MAIN CABLE. 